FaCD Online Syndrome Fact Sheet

Last updated: 05 Mar 2010

Name: Bardet-Biedl syndrome

Synonym: BBS, Bardet-Biedl syndrome, type 1-12: BBS1-12,Laurence-Moon-Biedl syndrome

Mode of Inheritance: AR

Genes

BBS1, mapped to 11q13
BBS10, mapped to 12q
BBS11, mapped to 9q33.1
BBS12, mapped to 4q27
BBS2, mapped to 16q21
BBS3, mapped to 3p12-q13
BBS4, mapped to 15q22.3
BBS5, mapped to 2q31
BBS6/MKKS, mapped to 20p12
BBS7, mapped to 4q27
BBS8, mapped to 14q32.11
BBS9, mapped to 7p14

Tumor features (possible)

glioma of the brain
renal cell cancer, clear-cell (Grawitz tumor)

Non-tumor features

brachydactyly, of feet
brachydactyly, of hands
dental abnormalities
developmental delay/mental deficiency/mental retardation
hearing loss, conductive
hypogonadism
obesity
polydactyly, postaxial
renal anomalies
renal dysplasia
retinitis pigmentosa
rod-cone dystrophy

Comment

This disorder (BBS) is characterized by postaxial polydactyly, central obesity, rod-cone dystrophy, mental retardation and renal dysfunction.

Beales et al.[1] observed 3 cases of clear cell renal cell carcinoma (diagnosed at age 37, 40 and 52, respectively) among 180 parents of BBS patients. This is more than expected in the normal population (p=0.0007). The authors calculated that parents of BBS children have a relative risk of 17( 95% c.i.= 3.6-49.9) to develop clear cell renal cell cancer before the age of 55 years. One of the tumors showed loss of heterozygosisty at the BBS1 locus. The authors suggest that the BBS genes may be implicated in the development of renal cancer (and renal malformation). In contrast, Hjortshøj et al found no evidence for an increased cancer risk in BBS patients and there relatives[2]. Metastasized clear cell renal cell cancer was diagnosed in a 30-year-old male with BBS[3]

Yamada et al reported a brain stem glioma in a BBS patient[4].

References

[1] Beales PL, Reid HAS, Griffiths MH, Maher ER, Flinter FA, Woolf AS. Renal cancer and malformations in relatives of patients with Bardet-Biedl syndrome. NEPHROLOGY DIALYSIS TRANSPLANTATION 2000; 15(12):1977-1985.
[2] Hjortshøj TD, Grønskov K, Rosenberg T, Brøndum-Nielsen K, Olsen JH. Risk for cancer in patients with Bardet-Biedl syndrome and their relatives. American journal of medical genetics. Part A 2007; 143(15):1699-702.
[3] Zaldivar RA, Neale MD, Evans WE, Pulido JS. Asymptomatic renal cell carcinoma as a finding of Bardet Biedl syndrome. Ophthalmic Genet. 2008 Mar;29(1):33-5.
[4] Yamada K, Miura M, Miyayama H, Sakashita N, Kochi M, Ushio Y. Diffuse brainstem glioma in a patient with Laurence-Moon-(Bardet-)Biedl syndrome. Pediatric neurosurgery 2000; 33(6):323-7.